Part of the game? National Football League great John Mackey shows off his Super Bowl V and Hall of Fame rings. Mackey died at age 69 in 2011 of frontotemporal neurocognitive disorder, a condition marked by extreme confusion and the need for full-time assistance. Many cases of neurocognitive disorder, like Mackey’s, are apparently the result of repeated sports injuries to the head, a link implicitly acknowledged by the NFL with their implementation of the “88 Plan” (named after Mackey’s jersey number), which helps pay the cost of nursing home care and day care for football veterans with such problems.